Yb-bodies are perinuclear foci in Drosophila ovarian somatic cells, which are thought to be the site of PIWI interacting RNA (piRNA) synthesis (OSCs). Yb bodies are multivalent condensates that are formed by Yb-Yb homotypic interaction and interacvtion with flamenco RNA transcripts, which are the source of transposon-repressing piRNAs (31267711).
Hirakata S, Ishizu H, Fujita A, Tomoe Y, Siomi MC. Requirements for multivalent Yb body assembly in transposon silencing in Drosophila. EMBO Rep. 2019 Jul;20(7):e47708. doi: 10.15252/embr.201947708. Epub 2019 Apr 30. PMID: 31267711; PMCID: PMC6607011.